A common problem with FOC Onslaught is for the green blaster he comes packaged with to get stressed. The connections on his vehicle mode (to his arm) force the plastic further than it can take. That, and let's face it:

Onslaught isn't Onslaught without twin huge cannons!

The FOC Onslaught Upgrade Kit provides fixes to both these issues. A new Hinge Blaster and two Hinges relieve plastic stress with a new attachment point while Twin Cannons provide the firepower and silhouette Onslaught deserves.

In robot mode, Onslaught gets a new pistol and two shoulder-mounted cannons, surprisingly not from Swindle!

Twin Cannons mount on Onslaught using the combiner ports on his shoulders. They can also be handheld using the 5mm pegs.